1. Field of the Invention
This invention relates to the decontamination of ground water and soil, in particular to the removal of such water-immiscible dense organic compounds as perchloroethene (C2Cl4, PCE), trichloroethene (C2HCl3, TCE),and dichloroethene (DCE).
2. Prior Art
It is known that potassium permanganate can oxidize PCE dissolved in groundwater and thus reduce its concentration. However, where non-aqueous phase dense organic compounds are present, ground water concentrations may rebound over time as equilibrium between aqueous and non-aqueous phases is reestablished.
There have also been trials of a cosolvent flushing method, in which PCE was removed from a source area containing dense non-aqueous phase liquid (DNAPL) PCE at a former dry cleaning facility as an extracted groundwater/alcohol/PCE ternary mixture, and approximately 70 percent of the mass of non-aqueous phase PCE was recovered from the test zone in four days. This method, while showing some promise, presents a formidable problem of disposal or recycling of the extracted ternary mixture.